to calculate pi you can use the Nilakantha Series.
Step-by-step explanation:
15) 50 ÷ 2 = 25
17) Mean = 301, Mode = 40-50
(10+20) ÷ 2 = 15, (20+30) ÷ 2 = 25, (30+40) ÷ 2 = 35
(40+50) ÷ 2 = 45, (50+60) ÷ 2 = 55, (60+70) ÷ 2 = 65
(70+80) ÷ 2 = 75
• 15×4 = 60, 25×8 = 200, 35×10 = 350, 45×12 = 540
55×10 = 550, 65×4 = 260, 75×2 = 150
Mean = (60+200+350+540+550+260+150) ÷ 7
= 2110 ÷ 7
= 301.4285....
= 301
Mode : the highest frequency
Here, you have to foil the equation.
Distribute 4x to all sides, then distribute the -3 to all sides. Next, combine like terms. If you do this, your answer will be
Answer:
Twice a number decressed by five
So the number of pencils bought can be represented by an equation:

, where n is the number of notebooks bought. Since Helen bought 5 notebooks, simply plug 5 into n:

. So Helen bought 12 pencils.